PORTLAND – Even a few tense moments and a flurry of shots at the finish didn’t dissuade Portland coach Caleb Porter from believing that the Timbers were going to beat the Sounders.

“We dodged some bullets, for sure,” he said. “But in the end I thought it was our game to win.”

Kalif Alhassan scored late in the first half and the Timbers held on for a 1-0 victory over Cascadia Cup rival Seattle on Sunday night, denying the Sounders a chance to clinch a playoff berth.

The Timbers (13-5-14) moved into first place in the MLS Western Conference, pulling them closer to the postseason spot with two games left. Portland has not lost in six straight overall matches, and hasn’t lost at home in 14 straight.

“Everybody is dialed in,” midfielder Will Johnson said. “Everyone is on board.”

It was the third straight loss for the Sounders, who fell to Vancouver Whitecaps 4-1 on Wednesday night. The Sounders (15-11-6) dropped into third place in the conference standings as the playoffs loom.

Seattle star Clint Dempsey, captain of the U.S. national team, appeared to injure his shoulder in the first half and twice went to the sideline to seek treatment. But he returned for the second half.

“He was trying his best, but he was carrying his shoulder,” Seattle coach Sigi Schmid said. “He couldn’t go into challenges and tackles, he couldn’t run normally.

“All those things affected him.”

With the Seattle loss, Vancouver claimed the supporters-created Cascadia Cup, an annual three-way competition among the Sounders, Whitecaps and Timbers.

The Timbers were last season’s recipients of the Cascadia Cup, which was introduced in 2004 when all three teams were part of the United Soccer Leagues First Division.

It was the third meeting this season between the two teams, but first in Portland. The first ended in a 1-1 draw and Seattle claimed the second 1-0.

The Timbers have not earned a playoff berth since joining MLS in 2011.